Ingredients

Step by step

1. Preheat the oven to 180°C, fan 160°C, gas 4. Lightly butter a 900g loaf tin that measures about 20cm x 9cm x 8cm deep and line with a strip of baking paper, so that the excess hangs over the sides of the tin (this will make removing the loaf easier).
2. Put the butter into a pan and place over a medium heat until melted. Remove from the heat, and add the Guinness and cocoa powder, whisking together until smooth. Whisk the sugar, milk and eggs into the Guinness mixture.
3. In a bowl, mix together the flour, bicarbonate of soda and ¼ teaspoon salt. Add the Guinness mixture and whisk briefly until smooth and combined. Pour the mixture into the prepared loaf tin and bake in the preheated oven for 40-45 minutes or until a skewer inserted into the middle of the cake comes out clean. Allow the cake to cool in the tin for 15 minutes before carefully lifting out; cool on a wire rack.
   Tip

   Not keen on Guinness? Substitute it with Coca-Cola – it delivers that extra level of flavour just as well.
4. To make the frosting, put the butter into a medium bowl and, using an electric mixer, beat until smooth and creamy. Add the icing sugar in 3 stages, mixing until combined. Once all the icing sugar has been added, beat it on high speed until it's light and fluffy. Add the cream cheese and vanilla and beat until just fully combined (if you beat it for too long, the frosting will become too loose).
5. To decorate, spread the frosting over the top of the cooled cake and finish with some chocolate shavings – make these by running a flat-bladed vegetable peeler along a chocolate bar.